This circuit is from an article that appeared in the June 1974 issue of Radio Electronics magazine. The circuit used integrated circuits and transistors of the time and included the power supply.
This filter, from an audio publication from 1977, passes the frequency range corresponding to the...
In the figure we have three voltage doubler configurations that can be used in high and low...
This circuit was found in Motorola documentation from 1966. The lamps are according to power and...